1. Field of the Invention
The invention relates to a printer with a revolving type belt.
2. Description of Prior Art
The German Offenlegungsschrift No. 2 344 923 describes a type printer with a revolving, endless type carrier guided on two rolls spaced from each other. This type carrier has a straight section in which the types are printed and which extends parallelly to the printing line. In addition, the type carrier is provided with emitter marks which are sensed by a stationary sensor. The type belt is contact friction driven and is made of relatively thin non-ferrous steel. Along is edge the belt is provided with a plurality of spaced fingers, each supporting a raised type or character.
The German Offenlegungsschrift No. 2 224 951 refers to a printer with a type carrier moving along the printing line on the side of the document to be printed and being provided with types arranged on spaced fingers, as well as with selectable print hammers. The type carrier preferably consists of a flexible, endless metal belt.
Also known are steel type printers in which the characters, rather than being disposed on finger-shaped segments, are located on the steel belt direct.
All of these arrangements are unsuitable for high belt and thus high printing speeds, because of the high drive speeds and the resulting high degree of wear and deformation in the type sections (provided that the types, rather than being disposed on the steel belt, are electrochemically etched on same). The high type belt wear occurs especially on the platen which is a steel plate in most cases and on which the belt slides. If one tolerates a disproportionately high wear of the type carrier at high printing speeds, one will equally have to tolerate the fact that the type carrier has to be exchanged at short intervals. This, however, is disadvantageous for cost reasons.